Nu’man b. Bashir (RA) reported: My father brought me to Allah’s Messenger (peace be upon him) and said: I have donated this slave to my son. whereupon he said: Have you made (such) donation to every one or your sons? He said: No. Thereupon he (the-Holy Prophet) said: Then take him back.
Sahih Muslim, Book 24, Hadith 16






